Change Drayton RTS1 thermostat with a Drayton Digistat + 3

[abay710]

Hi

I am looking to change my Drayton RTS1 thermostat, with a Drayton Digistat + 3.

I have a Potterton Puma combi at the moment. There are 3 wires going to the thermostat at the moment

Red (live)
Yellow (switched live)
Blue (netural)

Someone once told me that the Potterton Puma, although being a combi was unusual and ran on 230V rather than low voltage like other combi boilers.

Will this make a difference when i change to the new thermostat, the fact that the digistat is volt free and I wont be connecting the netural wire?

Cheers for any help

 

[D_Hailsham]

Someone once told me that the Potterton Puma, although being a combi was unusual and ran on 230V rather than low voltage like other combi boilers.

All boilers need a 230v supply. The Puma is unusual in that the external controls (programmer, thermostat) work at the 230v level. Most combi boilers connect external controls to the PCB which works at 24v DC.

Will this make a difference when I change to the new thermostat, the fact that the digistat is volt free and I wont be connecting the neutral wire?

Assuming it is the wired and not the wireless Digistat +3, the answer is No.

You need a volt free stat as all it is doing is closing a connection between two terminals on the boiler.

As for the unused neutral, I would suggest disconnecting at the boiler and wrapping both ends in insulating tape, so future owners will know it is not required.

 

[abay710]

Thanks for that.

So why is there a netural. Why does the old RTS1 need a neutral but the Digitstat doesnt.

It is the wired digistat i am getting, but out of interest, why would I not have been able to get the wireless one?

Cheers again

 

[D_Hailsham]

Why does the old RTS1 need a neutral but the Digitstat doesnt.

The RTS1 needed a 230v supply to run the temperature sensing device; so it needed a neutral. The Digistat uses a different sensor which is powered by the internal batteries, which also light the display

It is the wired digistat i am getting, but out of interest, why would I not have been able to get the wireless one?

Yes you could have used a wireless version. The wiring would have been different as the receiver (bit wired to the boiler) would have required a neutral! I didn't want to give you wrong instructions

 

[abay710]

Thats great, thanks for your help.

Thats it ordered, so hopefully all will go smoothly when i install it next week.

Thanks again